1. Field of the Invention
The present invention relates to fault management of a circuit section of a switching equipment such as an exchange or a router which includes a processor such as a frame relay, and more particularly to a management system for an recoverable and critical fault.
2. Description of the Related Art
A switching equipment such as an exchange or a router includes a processor which performs central control, a switch section, and a circuit processing section (refer to, for example, Japanese Patent Laid-Open No. Hei 08-256178 or No. Hei 06-350695). The circuit processing section sometimes includes a local processor for performing protocol processing or routing processing for input/output packets or load distribution (refer to, for example, Japanese Patent Laid-Open No. Hei 09-289524). Generally, a communication protocol is formed in a hierarchical model including a physical layer which is the lowermost layer, a data link layer and other higher layers, and the layers are definitely separate from each other. The processor takes charge of processing of packets and data in the data link layer or higher layers.
Conventionally, if an unrecoverable and critical fault about the processor occurs with the circuit processing section of an equipment of the type described above, then it is necessary for an operator to manually input a compulsory reset instruction to the circuit processing section from a console to compulsorily cut a circuit in order to prevent a disabled condition of data transmission/reception or a condition wherein disconnection of a circuit for preventing such a disabled condition of data transmission/reception is impossible as disclosed in Japanese Patent Laid-Open No. Hei 06-075876.
FIG. 1 shows a fault circuit compulsory resetting system disclosed in Japanese Patent Laid-Open No. Hei 06-075876. Referring to FIG. 1, if an operator command for changing a state of a communication circuit 104 is inputted from a console 105 by an operator, then a command analysis section 116 of a host computer 101 analyzes the operator command. If the operator command is a communication circuit connection command, then the command analysis section 116 sends a connection request to a circuit state changing section 115. However, if the analyzed operator command is a communication circuit disconnection command, then the command analysis section 116 sends a disconnection request to the circuit state changing section 115. On the other hand, if the analyzed operator command is a command for compulsorily resetting a communication circuit, then the command analysis section 116 sends a compulsory reset request to a compulsory circuit disconnection section 117.
If the circuit state changing section 115 receives a circuit connection request from the command analysis section 116, then it performs connection of the circuit through a circuit control section 113 and sets a circuit state of a circuit state management table 111 to “connected”. On the other hand, if the circuit state changing section 115 receives a disconnection request of a circuit from the command analysis section 116, then it performs disconnection of the circuit through the circuit control section 113 and sets the circuit state of the circuit state management table 111 to “disconnected”. Further, if the circuit state changing section 115 receives a fault notification of a circuit from the circuit control section 113, then it sends a fault notification of the circuit to a data transfer section 114 and sets the circuit state of the circuit state management table 111 to “fault”.
If the data transfer section 114 receives a data transmission/reception request from an on-line information processing program section 112, then it searches the circuit state management table 111 for a pertaining communication circuit using a circuit identification name as a key and discriminates whether or not the circuit state of the communication circuit is “connected”. If the circuit state is “connected”, then the data transfer section 114 performs communication of data with a terminal equipment 102 and an external host computer 103 through the circuit control section 113. However, if the circuit state is not “connected”, then the data transfer section 114 sends a transmission/reception failure notification.
On the other hand, if the data transfer section 114 receives a fault notification from the circuit state changing section 115 or the compulsory circuit disconnection section 117, it stops the data communication and notifies the on-line information processing program section 112 that transmission/reception of data is abnormal.
If the compulsory circuit disconnection section 117 receives a compulsory resetting request of a circuit from the command analysis section 116, then it sends a fault notification to the data transfer section 114 and sets the circuit state of the circuit state management table 111 to “fault”.
However, the fault management system described above is disadvantageous in that, since it is necessary for its operator to enter a compulsory reset command by a manual inputting operation into the console, considerable time is required until a fault is removed after the fault occurs. Consequently, it is a matter of course that communication processing cannot be performed before the fault is recovered. Besides, if the fault occurs about the processor which performs data transmission/reception processing, then there is the possibility that the circuit section may malfunction and signal illegal data, which should not originally be transmitted, to a terminal equipment or the like (associated apparatus) on the opposing side to the circuit section, resulting in a malfunction of the associated apparatus. Even if the circuit section does not malfunction, it likely occurs that the processor stops and processing on the data link layer or on a higher layer stops while the physical layer operates normally, and it is difficult for the associated apparatus to discriminate the fault.